There's always been something dodgy about those blue masks. Specifically, they're full of chemicals that can cause irritation, and some people are more allergic than others and some masks are worse than others.

My mother was a nurse. I remember how when they switched brands of masks one time, she got severe "macne" (mask acne). As I recall, she and some other employees had to buy their own masks in a different brand until they convinced the hospital to switch back, because more people than usual were having reactions to the masks. And remember that people experiencing skin reactions were also breathing through those things and inhaling who knows what. Masks have always had issues.

While I think masks have a limited place in certain settings - there is definitely something to be said for keeping spit out of open wounds during surgery - they are not risk free. Imposing them on the general public, as well as on medical personnel in non-surgical settings, was not only pointless, but also came with health consequences.